The boundaries between archaeological science and some other branches of archaeology, such as environmental archaeology and bioarchaeology, are somewhat blurred. For example, studies involving pollen analysis (palynology) figure prominently in archaeological science journals, but most palynological research is not done on archaeological materials or deposits per se but ‘off site’, directed at answering questions about past environments and human–environment interactions. Similarly, DNA studies and isotopic studies of human diet may be considered as core elements within the sub-field of bioarchaeology.